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Date and Time of the Query: 2019-06-26 T07:45:28 PDT
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For refcode 1974AJ.....79.1220C:
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Copyright by American Astronomical Society. Reproduced by permission
1974AJ.....79.1220C Spectra of sources in the NRAO 5000-MHz surveys. Condon, J. National Radio Astronomy Observatory, Charlottesville, Virginia 22901 Jauncey, D. National Astronomy and Ionosphere Center and Cornell-Sydney University Astronomy Center, Cornell University. Ithaca, New York 14850 ABSTRACT Spectral Indices for all the NRAO 5000-MHz S-survey sources in the declination range -2^deg^ < {delta} < +39^deg^ were determined from 318-MHz flux densities measured at Arecibo. The spectral index distribution for 278 sources stronger than 0.6 Jy is bifurcated, showing a secondary peak near {alpha} = 0. Both the normal-spectrum component and the fraction of flat-spectrum sources show the same changes with flux density that are found in the Pks 2700-MHz survey: the normal-spectrum sources steepen while the fraction of flat spectrum sources decreases with decreasing flux density. The normal-spectrum source population is shown to be quite different from the ones found in low-frequency surveys in that it favors nearby galaxies with low absolute radio luminosity. Its median spectral indexincreases with decreasing flux density, and these sources are not distributed randomly on the sky. These effects may be due to a local (z <~ 0.1) inhomogeneity rather than cosmological causes.
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